This invention relates generally to the field of protective mats, covers or blankets and, more particularly, to the use of protective mats to protect the coating of a pipe during heating, grinding, welding, and brushing operations.
Fusion-bonded epoxy coating (“FBE coating”) is a pipeline coating applied to a pipe prior to the pipe being delivered to the right of way for welding. To prevent the welding process from damaging the FBE coating, the coating stops short of each end of the pipe by about 2½ inches. However, at every weld made to join sections of pipe together, weld splatter or “spatter” tends to reach out a few inches farther than this 2½ inch buffer zone. The spatter melts into the FBE coating and damages it. If the coating is not repaired, the holes formed by the weld spatter in the coating makes that portion of the pipe subject to rust and deterioration.
Because of the damage to the coating caused by weld spatter, almost all pipeline operators require that the FBE coating be protected during the welding process, that is, during heating, grinding, welding, and brushing operations. Welders have tried various methods to protect the coating. These methods range from techniques aimed at reducing weld spatter to various coverings aimed at protecting the coating. An assortment of coverings have been tried, including cardboard, carpeting, wet rags, rubber bands or strips, auto floor mats, and specially designed welding blankets or mats. Each type of covering has its problems. Cardboard and carpeting do not always conform to the pipe's surface, they easily slip, blow, or get knocked off of the pipe, and they quickly burn up. Wet rags solve the conforming and slipping problem of cardboard and carpeting but may not be used due to welding codes and procedures. Rubber strips are allowed, and while they help solve the conforming and slippage problem of cardboard, they do little to solve the blowing off, knocking off, and burning up problem. Auto floor mats are not much different than the rubber strips. Welding mats do not easily burn up but, like these other materials, slip, blow, or get knocked off of the pipe.